U.S. Pat. No. 5,988,133 issued to Agapiades et al. on Nov. 23, 1999 teaches a rotating disc valve that opens an closes exhaust and intake ports of a cylinder head in order to provide communication with the combustion chamber. This disc is rotatively mounted within the cylinder head of an internal combustion engine having beveled gear teeth at its outer perimeter and a plurality of equally-spaced ports about its center of rotation which will meet with a light number of sets of exhaust and intake conduits within the cylinder head for cyclic indexing therewith. These exhaust and intake conduits lead from the combustion chamber to a respective exhaust and intake manifold. The disc valve rotates synergistically with the crankshaft via a chain mounted to a sprocket on the crankshaft as well as to a second sprocket which is in operative communication with a pinion gear having bevel teeth meshed with the bevel teeth of the disc 12.
Therefore, the disc valve allows for intake and exhaust through the piston exhaust in and from a combustion chamber formed by the engine cylinder which contains a piston.
A drawback of the prior art design is that combustion within the cylinder combustion chamber is not sealed. Other drawbacks of the prior art include, and without limitation: the positioning of an igniter such as sparkplugs on the disc valve itself, hence causing the sparkplug to turn therewith; the lack of lubrication between the disc valve and the cylinder head; the inflexibility of the timing gear (top sprocket mounted to the pinion which acts on the disc valve); the fact that the ports of the rotating disc valve cannot be modified in size during operation; the fact that the ports are symmetrical to one another and hence act in codependence, which limits the configuration of the cylinder head as well as the overall operation of intake and exhaust; the fact that the chain mounted on the sprockets moves in a constant and uniform way which does not allow retarded intake and exhaust port openings; the fact that the disc valve is directly mounted within the cylinder head.
There thus remains a need for an improved disc valve system and an engine comprising same.